Research On The Process Of Preparing Ceramsite Proppant From Andalusite Tailings

Hydraulic fracturing technology is an important means to increase production in oil and gas fields.As an important part of hydraulic fracturing,the performance of proppant has a significant impact on the oil and gas fracturing effect.It can not only make better use of resources,but also protect the environment if the proppant can be prepared by other mineral or waste.And there are a lot of andalusite tailings in Xinjiang,Henan and other places of andalusite mining,which take up valuable land resources and generates a lot of dust and pollut the environment heavily.So it has important practical significance that using andalusite tailings to prepare proppant and the coated one,which can solve the harm of andalusite tailings and be effectively used.The main raw materials for the preparation of andalusite ceramsite were bauxite and andalusite tailings which had been light burned.The effect of the addition of light burned andalusite tailings on the properties of ceramsite was considered.The optimum preparation formulations of ceramsite for the 50%addition of light burned andalusite tailings was determined by discussing the effect of various additives on the properties of ceramsite and basic physical performance test,XRD,SEM.With orthogonal and single factor experiiment of the basic physical performance test,the optimum coating formulations of ceramsite were determined.The results showed that the raw material was calcinated under the temperature at 9000C and kept constant about 2.5h,and the weightlessness rate was the largest,and the grain size was decreased,and the content of each oxide was improved,and the mineral composition had a great change.In the preparation process of andalusite ceramsite proppant,with the increase of amount of the light burned andalusite tailings,the broken rate of the ceramsite increased,and when the amount was 50%,the broken rate reached 10.49%,exceed the industry standard of 9.0%.For the 50%addition of light burned andalusite tailings,the optimal preparation formulations of the ceramsite was obtained as follws:when the mass addition of iron oxide powder was 1%and the time of calcining was 2h at 1260 'C,the volume density of proppant was 1.47g/cm 3 the apparent density was 2.78 g/cm3 and the broken rate was 8.58%,which met the industry standard.The best conditions of the andalusite ceramsite coated was followed:gel concentration was 0.11g/ml,the mass ratio of the core and wall was 5,emulsifier concentration was 0.03 g/ml,the volume ratio of oil and water was 10,and through variance analysis,the mainly influence factors for ceramsite coated were the core wall ratio,and the next one were emulsifier concentration,oil/water concentration and gel concentration.After the proppant coated,its unbroken capacity was greatly improved,and the volume density and apparent density had a certain degree of reduction,which could effectively reduce the cost of carrying liquid and pumping equipment.For annual production capacity of 10 million tons of andalusite ceramsite proppant,the economic evaluation had been preliminary carried out,and the results showed that the project had good profitability.